Sepsis resulted from transfusion of bacterially contaminated blood components, particularly platelets, is an on-going medical problem that frequently causes mortality or serious morbidity. The incidence of bacterially contaminated platelets and red cells is 1 in 2,000 to 3,000, and 1 in 30,000, respectively, resulting in 3,000- 4,500 sepsis cases yearly, of which 500-750 cases are severe and many are fatal. In contrast, the incidence of transfusion-transmitted viral infections is currently estimated to be between 1 and 4 per million blood components, or 25-100 cases a year. Bacterial infection due to platelet transfusion can be minimized with the use of an effective bacterial detection test that is rapid, specific, inexpensive and sensitive for multiple bacterial species. A test that meets these requirements is currently not available. We propose to use our microparticle based amplification (MBA) technology and a novel class of bacterial markers to develop a bacterial detection test for such intended use. The MBA technology, when employed with the novel class of bacterial markers, should permit the development of a rapid, inexpensive, specific and sensitive bacterial test. In this Phase I study, Cellex will verify the feasibility of the technology for use in bacterial detection in platelet concentrates by (1) designing and formulating an assay, (2) optimizing the assay protocol, and (3) evaluating the assay performance in terms of speed, specificity and sensitivity. A successful outcome of this Phase I study will lead to a Phase II study, which will demonstrate the performance of the test in clinical settings (e.g., transfusion services in hospitals or blood banks). The successful outcome of Phase II study will lead to the commercialization of the test, which will contribute to the improvement of safety of our nation's blood supply.